How Many Solar Panels To Charge An Electric Car?

Typically, you would need between seven and 12 solar panels to charge an electric car. While this estimation is a starting point, a qualified solar panel installer will be able to give you a precise assessment of your needs. 

In this article, we will look at factors that affect the number of solar panels needed to charge an EV, how to work this out, and what influences solar panel efficiency. 

How To Calculate The Number Of Solar Panels Needed To Charge An Electric Car?

To calculate the number of solar panels needed to charge an electric car, you will need to consider factors like energy consumption and solar panel efficiency. However, solar panels are worth it when it comes to charging your EV thanks to the savings on energy costs and reduction of your carbon footprint.

Electric vehicle battery size

The battery storage capacity will affect how much solar power can be stored. Larger vehicles have larger battery storage, while small, compact EVs usually have a smaller battery system. Many EVs have a battery capacity of 40 kWh, but newer EVs can have around 100 kWh. The larger the battery capacity, the more solar panels are needed to charge the battery.

EV charging speed

How fast you charge an EV with solar panels will also impact how many panels are required. 

A level 2 EV charger may require additional solar panels since more energy is required for faster charging. If you want to charge faster, you’ll need to generate that same amount of energy in a shorter time. 

Size of the solar panels

The number of solar panels required to charge an electric car is also dependent on the size of the panels. The higher the wattage output, the more electricity they produce, which means you may need fewer panels.

Sunlight hours

The amount of sunlight you get in your area will make a huge difference as well. If you are in an area that gets a lot of sunlight, you may need fewer solar panels for EV charging.

Battery storage

If you have battery storage for your solar panels, they can collect solar energy during the daylight hours. Depending on how much energy the battery system can store, it may influence how many solar panels are needed. If there this enough power in your batteries, it can reduce the number of panels needed to generate enough power for immediate charging.

Calculation

1. Calculate your car’s electricity consumption in kWh per day.
   • Example: 9.5 kWh daily.
2. Calculate the daily energy production for a solar panel – (number of daylight hours) x (solar panel kW output).
   • Example: If you get 5 daylight hours and have a 0.3 kWh solar panel, it can produce 1.5 kWh of energy per day.
3. Final calculation: (average daily energy consumption) / (daily energy production) = number of solar panels needed to charge an EV.
   • Example: 9.5 kWh (average daily energy consumption) / 1.5 kWh (daily energy production) = 6.33 (7 solar panels)

Factors That Influence Solar Panel Output Efficiency

It is crucial to ensure your solar panels work optimally so your electric vehicle can charge efficiently. With no fuel costs to worry about, solar charging becomes an attractive option. 

Sunlight hours

How much sun the solar panels receive will directly affect their output. Solar panels situated in areas with more sunlight tend to produce more energy.

Quality of the solar panels

Different brands have different quality standards. This can affect their overall efficiency. While their initial cost may be higher, they may be able to produce more energy, helping you save on energy bills and reduce your carbon footprint.

Shade

Solar panels that lie in shadow tend to be less efficient. This can reduce the overall effectiveness of any connected solar panels.

Dirt

When dirt and debris land on the solar panels, it can reduce their efficiency by blocking the amount of direct sunlight.

Solar PV system setup

The setup and connections between solar panels can influence how much renewable energy is available. Even the solar battery storage system can affect the outputs. For example, different setups, like connections in parallel or series, can increase or decrease solar energy production when there is shading. 

Solar panel temperature

The temperature of the solar panel system can affect their output. If the panels get too hot, their voltage output drops, which reduces their power generation.

Components

The different components, like a solar inverter unit and the batteries for storage, can affect the overall solar power output. For example, a less efficient converter will require more solar panels to create the same amount of energy.

FAQs

Do I still need national grid power if I charge my EV with solar power?

If you have sufficient solar power, you can reduce your reliance on fossil fuels to generate electricity and instead use your own solar panels to generate electricity.

Can I charge an EV at night with solar panels?

While it is possible to charge electric vehicles during the day with solar power, if your solar PV system has battery storage, then it is possible to use the stored power to charge your electric car overnight.

Final Thoughts

Solar panel charging for electric cars is becoming increasingly popular thanks to the substantial cost savings.

Contact us, at Eco Happy, today if you’re interested in using solar power to charge your electric car. We’re your go-to installation expert for all things renewable energy!